MUNICH, GERMANY — Trixter (www.trixter.de), which has German offices in Munich and Berlin, as well as Los Angeles, was responsible for more than 300 VFX shots that appear in Avengers: Age of Ultron. The studio’s work included effects for Quicksilver and Scarlet Witch, and the first time audiences see Ultron (Mark I). According to VFX supervisor Alessandro Cioffi, the studio got involved in early 2014, collaborating during preproduction with the film’s visual effects supervisor, Christopher Townsend.
“We were requested to investigate a look for Quicksilver and his colleague,” says Cioffi of the studio’s initial work. “This started during the time of Captain America: The Winter Soldier. There’s a sequence at the end of the show where these characters were introduced. It was a great privilege for us to do the concept for the visual effects for these two characters and then apply [it].”
Quicksilver has the ability to run or move extremely fast. “He has a very peculiar and specific look in the movie,” Cioffi explains. “Scarlet Witch has telekinetic powers and mind control powers, and also needed some enhancements and CG effects to be explanatory in the live-action performance.”
All of the work was performed at Trixter’s Munich facility, which has a core team of 40-plus artists, but scaled up to approximately 100 during crunch time. This included delivering 80 final shots in time for the film’s trailer debut at Comic Con in San Diego last summer.
“We worked massively on the project. In proportion to our scale, we are a fairly small facility. Working on over 300 shots was quite a challenge,” he notes.
The visual effects that support Quicksilver’s motion went through several stages of development. “We did some preproduction work with Chris, trying to define the look and where the possibilities were, and what has been seen before and what we wanted to avoid,” says Cioffi. “The first phase was trying to figure out what we could have done in-camera.”
Cioffi says the team looked at a number of ways to visualize Quicksilver’s high-speed motion. One option was to use realtime, where the character is shown moving extremely fast in-frame. Another would be to show him moving at normal speed, but with the world around him appearing to slow down. And the third would be Quicksilver moving at normal speed, but with the world around almost frozen in time.
“All of these approaches have a different look and require different shooting techniques,” Cioffi explains.
Ultimately, Townsend and director Joss Whedon opted for a look that resembled shooting things “at 6fps, with a pretty open shutter angle,” recalls Cioffi. “You get a photographic, smeary effect — not just the direction of blur, but a very dynamic and curvy effect behind things that are moving fast. In order to achieve that with our compositing tool, the solution was to shoot pretty much everything in high-speed — at least the foreground, namely Quicksilver — with an Alexa. We were oscillating between 120fps and 72fps, depending on the shots, and always trying to shoot a clean plate or backgrounds.”
Trixter uses a combination of off-the-shelf software within its proprietary pipeline. For modeling, animation and rigging, the studio employs Autodesk Maya. Lighting is achieved using Katana and rendering is performed using a combination of RenderMan and Arnold. Side Effects Houdini is used for effects and The Foundry’s Nuke handles compositing.
“They are all standards, but are joined together in our pipeline, which is a living creature and has to adapt in specific cases,” he notes. “All of these assets play very well together. Efficiency is a key, so we need to stay agile and light in our workflow so that we don’t suffer too much.”
In the comic, Quicksilver emits silver particles that sometimes freeze in position. Subliminal images also appear along his motion path. This was achieved by freezing random frames here and there, and compositing them in a subtle way.
“Then there was the whole part of creating the CG trail, which makes the effect look interesting,” Cioffe adds. The CG trail has a blue-ish, cold tonality, with silvery, shiny reflections. This was created entirely in Houdini. "The process was not that straightforward, as we had to create rotomation of the character. We had to rotomate a dummy on him to recreate his motion. This dummy was the base for releasing the particles behind him.”
The studio had as many as 100 licenses of RenderMan. Some of the rendering resources were allocated to characters and effects, while others were reserved for Houdini and compositing operations.
“We have split renderfarms for the three main assets,” he explains. “I’d say we try to combine render power with process optimization. We try to find a good solution in the shading and the lighting not to overload the farm. I’ll say this, the bottleneck was elsewhere and not the rendering.”
ULTRON MARK I
Trixter also produced the assets for the Ultron Mark I — the first appearance in the film. “It’s the first time Ultron appears in the movie and it appears in a temporary shape, as a self-assembled robot,” says Cioffe. “He has an extraordinary look — very creepy and mysterious. This CG character has been enriched greatly by mister James Spader’s performance.”
Cioffe is also quite proud of the work the studio performed for the fight sequence at the Avengers’ headquarters. “This sequence, which we worked on entirely from A-Z, was for me, the most interesting thing we worked on. In terms of visuals, animation, rendering, integration and compositing especially, what happens at Avengers Tower during this fight is something that made me really excited and willing to work on this show…It was the sequence I love the most.”